The Billy Tipton Memorial Saxophone Quartet (now known as The Tiptons Sax Quartet) is a jazzsaxophone quartet from Seattle, Washington. They actually consist of five members (the fifth member being the quartet's drummer and percussionist). The name of the quartet was inspired by Billy Tipton, a jazz pianist and saxophonist, who upon his death was revealed to be anatomically female. Formed in 1988, they have toured frequently in North America and Europe, collaborated with Pat Graney Dance Company, taught workshops on improvisation and composition, and have recorded eight CDs.

Amy Denio is an original member of the Billy Tipton Memorial Saxophone Quartet, dating from the band's very first rehearsal at her house in the Fall of 1988. She composed for BTMSQ and organized tours and concerts until Spring, 1996. She took a hiatus from the band until 2002, when she and Jessica Lurie reformed the band, now named Tiptons Sax Quartet.

Marjorie de Muynck was an original member and co-founder of BTMSQ, playing and touring with BTMSQ from 1988-1995. Marjorie was a recording artist with Sounds True and Sound Universe. Her last CD was "Vibrational Healing Music" in which she composed music in her signature Earth key of Ohm, using field recorded crickets, cicadas, bees, birds and bats,and Arizona barrel cactus. Her unusual recordings include altered frequencies of each. Her other CD's include "In the Key of Earth", and "There's No Place Like Ohm", Vols 1 & 2. She studied Oriental Medicine for over 25 years, and received her Master in Music from Boston University. She was a pioneer in the field of Sound Healing, developing the Ohm Therapeutics and the Acutonics Sound Healing systems and has written two books on the subject, including an instructional DVD. She resided near Santa Fe, New Mexico for roughly 10 years, where she was working on her Doctor in Oriental Medicine, continuing her passion for field recording animals, musical composition and performing with various groups. Marjorie died on January 25, 2011, at the age of 58. Obituary for Marjorie de Muynck

John Otto, at the time named Babs Helle, is the other co-founder of BTMSQ (along with Majorie de Muynck) and played in the group from 1988-1990, a busy period of 50 performances for the quickly emerging group that established its public identity. John coined the group's name, the Billy Tipton Memorial Saxophone Quartet, and was known for his rich baritone sound, snappy suits and ties, and for his witty commentary in his MC role at BTMSQ shows, thereby creating much of the public persona of the group. After leaving BTMSQ, John went on to work in the performance production field, including touring with Ani DiFranco. He has since worked professionally as a transgender activist, and currently works as a librarian and as an information specialist after obtaining his Master in Library and Information Science degree from the University of Washington.